This Larry Jennings routine from Epilogue Special No. 3, Part 2, c. 1975, p. 269, was inspired by Bill Miesel's “Ambitious Ten” in Ibidem, No. 10, June 1957, p. 195. A year before Jennings published his routine, Ian Baxter learned it, made a couple of modifications, and released his version – openly admitting that he was beating Jennings to the punch – in his magazine, The Blueprint, Vol. 1 No. 1, July 1974, p. 4.
(It is worth mentioning that a version by Persi Diaconis, not published, made its way through the “underground” circa 1972, and this was possibly the direct inspiration for the Jennings – and presumably Cervon – routines. This information is from Max Maven, who learned the Diaconis routine in 1973 or '74.)
In Ultra Cervon, 1990, p. 22, Bruce Cervon describes his version “A Matter of Psychology,” and claims that it is the original version that he devised by reworking an idea by Ray Grismer that is not mentioned. He writes: “My friend Larry Jennings was the first to put methods for this plot into print (…) and consequently many believed the trick to be his invention.”